Correct focus with d/rebel

Sleepyd · 15 Feb 2006 at 23:36

Hi,
I've got a question about focusing the Rebel. I find focusing fine when you've got a subject like the below, but I wondered what the technique is when the subject itself is not covered by one of the focus points.

Should you focus using one of the points, re-compose by moving the camera slightly to the desired position then shoot? My only thought surrounding that is that you might slightly increase the distance between lens/subject - especially subjects a long distance away when using F2.8 for example. How do you cope with this? Any tips?

hoodmeister · 15 Feb 2006 at 23:42

Pretty much what you've said with focus // recompose.

If you know there is going to be action, then you can pre-focus on an area before the action even hits it. For example, in the shot above you could focus on some sand a few metres infront of the dogs (assuming zoom lens) and then fire the shutter when they hit the focal plane.

There's no surefire way, as far as I know, when using a focus system with "fewer" AF points. I guess if you shoot this kind of stuff a lot it's good reason to upgrade to a higher end model.

SCM · 15 Feb 2006 at 23:57

You can at least on the 20D set the auto focus to one point of your choice only. Not sure for the 350D maybe have a look at the instructions as one focus point you can use makes some shots easier.

SCM

RichDay · 15 Feb 2006 at 23:58

My 10D hasn't got that many more focus points! TBH I don't use them anyway - I forced my focus point to the centre in the camera options and use the focus lock facility to focus and then recompose the shot if I need to.

I don't trust the camera to focus on what I want it to....

DizMatt · 16 Feb 2006 at 00:03

prefocus and fire
or set it to use one of the 7 AF points
it's really quick to change focus points

ranarama · 16 Feb 2006 at 00:05

SCM said:
You can at least on the 20D set the auto focus to one point of your choice only. Not sure for the 350D maybe have a look at the instructions as one focus point you can use makes some shots easier.
SCM

Yes, you can set the focus point with the 350D. Hold down the far top right button on the back (the one with the matrix symbol above it) and use the scroll wheel to change the focus point.

Personally I find the easiest way (for still shots) is to set the focus point in the centre and recompose if I need to. It's rare that I've had to change.

SCM · 16 Feb 2006 at 00:14

ranarama said:
Yes, you can set the focus point with the 350D. Hold down the far top right button on the back (the one with the matrix symbol above it) and use the scroll wheel to change the focus point.

Personally I find the easiest way (for still shots) is to set the focus point in the centre and recompose if I need to. It's rare that I've had to change.

Wasn't 100% sure if the 350 was the same as only handled it once while deciding on cameras last year but it is a good feature.

SCM

AndyBorzi · 16 Feb 2006 at 09:59

I have the 300D and I always use the centre focus and recompose, I can never get the camera to focus where I want otherwise!!

I have an EOS 30 with eye control over the focus point, and even then I always use the centre! I was always giving myself eye strain trying to force the camera to focus where I am looking anyway!! I sometimes wondered what I looked like when trying to use the eye control

jhmaeng · 16 Feb 2006 at 14:49

In most cameras, the centre focus point is the most accurate (and in some cases, it's the only cross-type sensor out of all the available ones including the D50/D70) so you will often find that other focus points don't focus as quickly or accurately as the centre point.

PS. I'm pretty sure the theory that focus then recompose gives OOF pictures is false - even if it wasn't, it wouldn't affect the majority of pictures.